What is the purpose of an encryption algorithm?

The purpose of an encryption algorithm is to transform data into a secure format to prevent unauthorized access. This process involves converting readable information, known as plaintext, into a coded version, called ciphertext, which can only be deciphered by someone who possesses the appropriate key or password. The primary goal of encryption is to protect sensitive information from being accessed or understood by individuals who do not have the necessary authorization. This is crucial in maintaining confidentiality and data integrity, especially in cyber environments where threats and unauthorized access attempts are prevalent.

Other options don't align with the primary function of encryption. Creating a backup of data is focused on ensuring data redundancy and recovery rather than securing data against unauthorized access. Increasing data retrieval speed pertains to performance optimization, which does not apply to the security-focused goal of encryption. Lastly, data compression aims to reduce the size of data for storage efficiency, which is distinct from the security measures that encryption provides.